1. Field of Invention
The invention relates to a drive system for a parallel-type hybrid vehicle with an engine connected to a motor and more particularly, to a hybrid vehicle drive system having an automatic transmission provided with a motor.
2. Description of Related Art
Conventionally, a drive system for a parallel-type hybrid vehicle has an automatic transmission provided with both an engine and a motor/generator. The driving forces of both the engine and the motor/generator are transmitted to the transmission when the vehicle takes off, accelerates, or the like, and the motor/generator functions as a generator for assisting an engine-brake effect when the vehicle runs along a downhill road, brakes, or the like. Further, braking energy is regenerated in order to enhance fuel economy and to reduce the amount of exhaust gas. Such a drive system for a parallel-type hybrid vehicle is disclosed, for example in Laid-open Japanese Patent Application No. Hei. 5-24447 (Related art 1), U.S. Pat. No. 5,789,823 (Related art 2), and Laid-open Japanese Patent Application No. 2000272362 (Related art 3).
The hybrid vehicle drive system disclosed in related arts 1 and 2 is structured such that a rotor of a motor is directly fixed to a torus external diameter portion of a torque converter, and a stator is disposed at an outside diameter side of the rotor. The drive system disclosed in related art 3 is structured such that a rotor is supported at a side wall of a motor housing by a bearing, and a stator is disposed at an external diameter side of the rotor and fixed to the motor housing.